Pani mo e tutu (yam-mashed bread)

Instructions

1. Peel the yam, cut it into pieces and boil it in salted water for 20 to 25 minutes, until it gives easily when pierced with a knife.
2. Drain it and mash it finely with a fork or potato masher.
3. Add the butter, milk and sugar, then mix until you get a smooth, creamy purée.
4. Cut the buns in half without fully separating them, or slice them in half horizontally.
5. Spread the yam purée over the inside of the buns.
6. Close them up and serve warm or at room temperature.